Governor Andrew Cuomo, Mayor Bill de Blasio and Police Commissioner Bill Bratton attended the mass for the 15-year veteran of NYPD who was affectionately called “Superman.”

Lemm grew up in Beemer, Nebraska, where he "stood out," Bratton said during his eulogy Wednesday.

"He’s remembered as a dedicated, hardworking, driven young man who loved football and most of all his family. After high school, Joe could have used his many talents in any number of ways, but as a teenager, with his entire life ahead, he made a choice that would come to define him and the man he would become: He chose selflessness. He chose sacrifice. He chose to serve."

He enlisted in the United States Air Force and served six years on active duty.

When he was discharged, he moved to New York and joined the NYPD in 2000. Lemm served in the NYPD’s Bronx warrant squad and was promoted to detective in January, 2014.

He was just a rookie police officer during the September 11, 2001 terror attacks, Bratton said.

"Joseph Lemm was a rookie NYPD cop then, and he was in the war from the start, sifting through the smoldering debris in the heartbreaking search for survivors," Bratton said. "Again, Joe was tested. And again, he chose to serve."

Lemm was on his third and final deployment as a member of the Air Force National Guard when a suicide bomber slammed an explosive-laden motorcycle into his patrol. He was due home in March.

"In 2008, the call to serve tugged at him again, and he joined the Air National Guard. Over the next six years, while still serving in the NYPD, he left the city three times to serve much different communities. Different, but no less in need of his help," Bratton said.

The five others who were also killed in the attack were Major Adrianna Vorderbruggen, Staff Sgt. Michael Cinco, Staff Sgt. Peter Taub, Staff Sgt. Chester McBride, and Staff Sgt. Louis Bonacasa.

"Three times, this war took (Lemm) thousands of miles away from his family, and the city and country he so dearly loved," Bratton said. "And now it has taken him farther than miles. It has taken him to a new post in eternity.

"For Air Force Technical Sergeant Joseph Lemm, his war is ended," he continued.

"Christine, Brooke, and Ryan: we will never stop caring for you. from this day, to every day thereafter, we will be with you. Because when Joe joined the NYPD, he joined a second family— and we are now yours. We will never forget you," Bratton said. "We will never forget Joe’s sacrifice, nor the debt owed to him, and to all of us who risk our lives on our behalf of others."

Lemm will be buried at a cemetery in Hawthorne.

"Today we say farewell to a hero of our time, and a hero for all ages, a patriot who centered his life on protecting others. We honor a United States serviceman, an NYPD detective, a husband, father, son, brother, and for so many, a friend," Bratton said.

"He was a hero when his city and his country needed one, an unceasing guardian at the gate. And now, a guardian at the gates of heaven."